The present invention is directed to a method of navigating and, in particular, to a method of navigating in a vehicle. More particularly, the invention is directed to a vehicle-based navigation system with smart map filtering, portable unit home-base registration, and multiple navigation system preferential use.
Position locators, such as Global Positioning System (GPS) receivers, signal triangulation receivers, compass-based systems, and inertial navigation systems, and the like, have become common in electronic devices, in general, and are particularly used in vehicles. The popularity of such systems is driven by consumer demand, low-cost electronics, and federal legislation which dictates that certain devices, such as cellular telephones, have position-locating capabilities. Position-locating technology is frequently used with mapping programs which provide map data, and the like, to aid in the determination of location and direction. Other related data, such as restaurants, shopping centers, street names, and scenic sites, often accompanies the map data. In addition to cellular telephones and vehicle-based installations, position locators may be included with other portable devices, such as Personal Digital Assistants (PDAs).
The widespread use of devices having position locators has caused certain redundancies to occur. For example, a consumer may have a position locator in his/her cellular telephone, PDA, or the like, and a position locator as a part of a vehicle-based navigation system. Indeed, it is expected that, in the future, vehicles will include a port which holds a portable device, such as a cellular telephone or a PDA, when the vehicle is in use and the portable device is removed when the occupant leaves the vehicle.
Map data from a map database is useful with a position locator in order to aid in the determination of location and/or direction. It is common to reside the map database, in whole or in part, in a vehicle-based storage device. For example, the map database could be provided on a CD ROM device which is useful with a CD reader included with the vehicle-based navigation system. Alternatively, a portion of a database could be downloaded to a local memory such as a flashcard at the beginning of a journey for use with that journey. All such devices require physical manipulation of a data storage media in order to transfer the map database to the vehicle. Such manual manipulation could be eliminated by residing the map database externally of the vehicle and transferring map data and related data to the vehicle on a real-time basis, such as over a communication link, which may be in the form of an RF communication channel. The problem with such systems is that the extent of the data transfer requirements would overwhelm the bandwidth capabilities of commercially available communication links.